What are "function terms" in the context of an ontology?
If you are looking for the functional verbs used in VA/VE (value analysis / value engineering) look at: 


https://www.valueanalysis.ca/functionanalysis.php
http://www.brcommunity.com/articles.php?id=b679
https://www.washoeschools.net/cms/lib08/NV01912265/Centricity/Domain/253/Social%20Studies/Marker%20Verbs.pdf